Display device

ABSTRACT

Provided herein may be a display device. The display device may include: a first connection electrode extending in a first direction, and electrically connected to a first power line to which a first power supply is applied; a second connection electrode spaced apart from the first connection electrode, and electrically connected to a second power line to which a second power supply is applied; a first electrode extending from the first connection electrode; a second electrode extending from the second connection electrode, and disposed in parallel to the first electrode with a predetermined distance therebetween; and a plurality of light emitting elements each including a first end electrically connected to the first electrode, and a second end electrically connected to the second electrode. Each of the first electrode and the second electrode may include a bent portion.

TECHNICAL FIELD

Various embodiments of the present disclosure relate to a display device, and more particularly, to a display device including subminiature light emitting elements each having a small size ranging from the nanoscale to the microscale.

BACKGROUND ART

Recently, a technique of manufacturing a subminiature light emitting element using a material having a reliable inorganic crystal structure and manufacturing a light emitting device using the light emitting element has been developed. For example, a technique of configuring a light source of a light emitting device using subminiature light emitting elements having a small size corresponding to a range from a nanoscale size to a microscale size has been developed. Such a light emitting device may be used in various electronic devices such as a display device and a lighting device.

To use a subminiature light emitting element in a lighting device, a display, etc., there is a need to connect the subminiature light emitting element and an electrode configured to apply a power voltage to the subminiature light emitting element. Various studies on a disposition relationship between the subminiature light emitting element and the electrode with regard to purposes of application, a reduction in space for the electrode, or a fabrication method have been carried out.

Methods of disposing the subminiature light emitting element and the electrode may be classified into a method of directly growing the subminiature light emitting element on the electrode, and a method of separately independently growing the subminiature light emitting element and then disposing the subminiature light emitting element on the electrode. In the latter case, if a light emitting element has a normal size, it is possible to stand the light emitting element vertically and connect the light emitting element with the electrode. However, in case that a light emitting element is a nanoscale subminiature light emitting element, it is difficult to stand the light emitting element vertically on the electrode.

DISCLOSURE Technical Problem

An object of the present disclosure is to provide a display device in which alignment of subminiature light emitting elements may be improved.

Another object of the present disclosure is to provide a display device having an improved view angle.

The present disclosure is not limited to the above-described objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

Technical Solution

A display device in accordance with an embodiment of the present disclosure may include: a first connection electrode extending in a first direction, and electrically connected to a first power line to which a first power supply is applied; a second connection electrode spaced apart from the first connection electrode, and electrically connected to a second power line to which a second power supply is applied; a first electrode extending from the first connection electrode; a second electrode extending from the second connection electrode, and disposed in parallel to the first electrode with a predetermined distance therebetween; and a plurality of light emitting elements each including a first end electrically connected to the first electrode, and a second end electrically connected to the second electrode. Each of the first electrode and the second electrode may include a bent portion.

The first electrode and the second electrode may respectively extend from the first connection electrode and the second connection electrode in a second direction intersecting the first direction.

The bent portion may have a shape protruding in the first direction.

Each of the first electrode and the second electrode may have a curved shape or a zigzag shape.

Each of the first electrode and the second electrode may have a shape formed by connecting a plurality of quadrant arcs.

Each of the first electrode and the second electrode may have a connection portion having a shape formed by connecting a plurality of quadrant arcs. An inflection point is included in the connection portion.

Each of the light emitting elements may include a rod-shaped light emitting diode having a size ranging from a nanoscale to a microscale.

At least some of the plurality of light emitting elements may be aligned such that a longitudinal direction thereof corresponds to a normal direction with respect to a direction in which the first electrode and the second electrode extend.

The first electrode or the second electrode may include a portion having a different width.

The display device may include at least one island electrode disposed between the first electrode and the second electrode without being directly connected to the first connection electrode or the second connection electrode.

Some of the plurality of light emitting elements may be disposed between the first electrode and the at least one island electrode. Other some of the plurality of light emitting elements may be disposed between the second electrode and the at least one island electrode.

The at least one island electrode may disposed in parallel to the first electrode and the second electrode with a predetermined distance therebetween.

The at least one island electrode may include a bent portion.

The plurality of light emitting elements may be connected in series and parallel to each other.

Each of the first electrode and the second electrode may further include a linear portion extending in a second direction intersecting the first direction.

A display device in accordance with an embodiment of the present disclosure may include: a substrate including an emission area; a first electrode disposed in the emission area of the substrate; a second electrode disposed in the emission area of the substrate on a layer identical with the first electrode, and configured to face the first electrode, and spaced apart from and electrically separated from the first electrode; and a plurality of light emitting elements disposed between the first electrode and the second electrode in a plan view. Each of the first electrode and the second electrode may include a bent portion in a plan view.

The display device may further include: a first contact electrode configured to connect a first end of each of the light emitting elements to the first electrode; and a second contact electrode configured to connect a second end of each of the light emitting elements to the second electrode.

The display device may further include a first island electrode and a second island electrode disposed between the first electrode and the second electrode. Distances between the first electrode, the first island electrode, the second island electrode and the second electrode may be equal to each other.

The first electrode, the first island electrode, the second island electrode and the second electrode may be disposed in parallel to each other.

Each of the first island electrode and the second island electrode may include a bent portion.

Details of various embodiments are included in the detailed descriptions and drawings.

Advantageous Effects

In a display device in accordance with embodiments of the present disclosure, alignment of subminiature light emitting elements may be improved, and a view angle may be improved.

The effects of the present disclosure are not limited by the foregoing, and other various effects are anticipated herein.

DESCRIPTION OF DRAWINGS

FIGS. 1 a and 1 b are respectively a perspective view and a sectional view illustrating a light emitting element in accordance with an embodiment of the present disclosure.

FIGS. 2 a and 2 b are respectively a perspective view and a sectional view illustrating a light emitting element in accordance with an embodiment of the present disclosure.

FIGS. 3 a and 3 b are respectively a perspective view and a sectional view illustrating a light emitting element in accordance with an embodiment of the present disclosure.

FIG. 4 is a plan view illustrating a display device in accordance with an embodiment of the present disclosure.

FIG. 5 is a circuit diagram illustrating an example of a sub-pixel included in the display device of FIG. 4.

FIGS. 6 a to 6 d are circuit diagrams illustrating an example of a unit pixel included in the sub-pixel of FIG. 5 .

FIG. 7 is a plan view illustrating an example of sub-pixels included in the display device of FIG. 4 .

FIG. 8 is a plan view illustrating an example of a first sub-pixel of the sub-pixels of FIG. 7 .

FIGS. 9 a to 9 d are sectional views illustrating examples of the unit pixel, taken along line I-I′ of FIG. 8 .

FIG. 10 is a plan view illustrating an example of the sub-pixel included in the display device of FIG. 4 .

FIG. 11 is a plan view illustrating an example of the sub-pixel included in the display device of FIG. 4 .

FIG. 12 is a plan view illustrating an example of the sub-pixel included in the display device of FIG. 4 .

FIG. 13 is a view for describing shapes of a first electrode and a second electrode of FIG. 12 .

FIG. 14 is a plan view illustrating an example of the sub-pixel included in the display device of FIG. 4 .

FIGS. 15 to 17 are plan views illustrating other examples of the sub-pixel included in the display device of FIG. 4 .

FIGS. 18 and 19 are plan views illustrating other examples of the sub-pixel included in the display device of FIG. 4 .

FIGS. 20 a to 20 d are circuit diagrams illustrating an example of the unit pixel included in the sub-pixel of FIG. 5 .

FIGS. 21 to 30 are plan views illustrating various examples of the sub-pixel (or the unit pixel) to which the examples of FIGS. 20 a to 20 d may be applied.

FIG. 31 is a circuit diagram illustrating an example of the unit pixel included in the sub-pixel of FIG. 5 .

FIG. 32 is a plan view illustrating an example of the sub-pixel of FIG. 31 .

MODE FOR INVENTION

Advantages and features of the present disclosure, and methods for achieving the same will be cleared with reference to embodiments described later in detail together with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims.

It will be understood that in case that an element or a layer is referred to as being “on” another element or a layer, it can be directly on, connected to, or coupled to the other element or the layer, or one or more intervening elements or layers may be present. Like reference numerals refer to like elements throughout.

It will be understood that, although the terms “first”, “second”, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For instance, a first element discussed below could be termed a second element without departing from the teachings of the present disclosure. In the present disclosure, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, same or similar reference numerals are used to designate the same or similar elements.

FIGS. 1 a and 1 b are respectively a perspective view and a sectional view illustrating a light emitting element in accordance with an embodiment of the present disclosure. Although a rod-type light emitting element LD of a cylindrical shape is illustrated in FIGS. 1 a and 1 b, the type and/or shape of the light emitting element LD according to the present disclosure are not limited thereto.

Referring to FIGS. 1 a and 1 b, the light emitting element LD may include a first conductive semiconductor layer 11, a second conductive semiconductor layer 13, and an active layer 12 interposed between the first and second conductive semiconductor layers 11 and 13. For example, the light emitting element LD may be configured of a stacked body formed by successively stacking the first conductive semiconductor layer 11, the active layer 12, and the second conductive semiconductor layer 13 in one direction.

In an embodiment, the light emitting element LD may be provided in the form of a rod extending in one direction. The light emitting element LD may have one end and a remaining end with respect to one direction.

In an embodiment, one of the first and second conductive semiconductor layers 11 and 13 may be disposed on the one end of the light emitting element LD, and the other of the first and second conductive semiconductor layers 11 and 13 may be disposed on the remaining end of the light emitting element LD.

In an embodiment, the light emitting element LD may be a rod-type light emitting diode manufactured in the form of a rod. Here, the term “rod-like shape” embraces a rod-like shape and a bar-like shape such as a cylindrical shape and a prismatic shape that is longer in a longitudinal direction than in a width direction (i.e., to have an aspect ratio greater than 1), and the cross-sectional shape thereof is not limited to a particular shape. For example, the length L of the light emitting element LD may be greater than a diameter D thereof (or a width of the cross-section thereof).

In an embodiment, the light emitting element LD may have a small size ranging from the nanoscale to the microscale, e.g., a diameter D and/or a length L ranging from the nanoscale to the microscale. However, the size of the light emitting element LD is not limited to this. For example, the size of the light emitting element LD may be changed in various ways depending on design conditions of various devices, e.g., a display device, which employs, as a light source, a light emitting device using a light emitting element LD.

The first conductive semiconductor layer 11 may include at least one n-type semiconductor layer. For instance, the first conductive semiconductor layer 11 may include an n-type semiconductor layer which includes one semiconductor material of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and is doped with a first conductive dopant such as Si, Ge, or Sn. However, the material for forming the first conductive semiconductor layer 11 is not limited to this, and various other materials may be used to form the first conductive semiconductor layer 11.

The active layer 12 may be disposed on the first conductive semiconductor layer 11 and have a single or multiple quantum well structure. In an embodiment, a cladding layer (not shown) doped with a conductive dopant may be formed over and/or under the active layer 12. For example, the cladding layer may be formed of an AlGaN layer or an InAlGaN layer. In an embodiment, a material such as AlGaN or AlInGaN may be used to form the active layer 12, and various other materials may be used to form the active layer 12.

If a voltage of a threshold voltage or more is applied to the opposite ends of the light emitting element LD, the light emitting element LD may emit light by coupling of electron-hole pairs in the active layer 12. Since light emission of the light emitting element LD can be controlled based on the foregoing principle, the light emitting element LD may be used as a light source of various light emitting devices as well as a pixel of the display device.

The second conductive semiconductor layer 13 may be disposed on the active layer 12 and include a semiconductor layer having a type different from that of the first conductive semiconductor layer 11. For example, the second conductive semiconductor layer 13 may include at least one p-type semiconductor layer. For instance, the second conductive semiconductor layer 13 may include a p-type semiconductor layer which includes any one semiconductor material of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and is doped with a second conductive dopant such as Mg. However, the material for forming the second conductive semiconductor layer 13 is not limited to this, and the second conductive semiconductor layer 13 may be formed of various other materials.

In an embodiment, the light emitting element LD may further include an insulating film INF provided on the surface of the light emitting element LD. The insulating film INF may be formed on the surface of the light emitting element LD to enclose an outer circumferential surface of at least the active layer 12, and may further enclose one area of each the first and second conductive semiconductor layers 11 and 13. Here, the insulating film INF may allow the opposite ends of the light emitting element LD that have different polarities to be exposed to the outside. For example, the insulating film INF may expose one end of each of the first and second conductive semiconductor layers 11 and 13 that are disposed on the respective opposite ends of the light emitting element LD with respect to the longitudinal direction, e.g., may expose two surfaces (i.e. upper and lower surfaces) of the cylinder rather than covering them.

In an embodiment, the insulating film INF may include at least one insulating material of silicon dioxide (SiO2), silicon nitride (Si3N4), aluminum oxide (Al2O3), and titanium dioxide (TiO2), but it is not limited thereto. In other words, the material that forms the insulating film INF is not limited to a particular material, and the insulating film INF may be formed of well-known various insulating materials.

In an embodiment, the light emitting element LD may further include additional other components as well as the first conductive semiconductor layer 11, the active layer 12, the second conductive semiconductor layer 13, and/or the insulating film INF. For example, the light emitting element LD may further include one or more fluorescent layers, one or more active layers, one or more semiconductor layers, and/or one or more electrode layers disposed on one end of the first conductive semiconductor layer 11, the active layer 12, and/or the second conductive semiconductor layer 13.

FIGS. 2 a and 2 b are respectively a perspective view and a sectional view illustrating a light emitting element in accordance with an embodiment of the present disclosure. FIGS. 3 a and 3 b are respectively a perspective view and a sectional view illustrating a light emitting element in accordance with an embodiment of the present disclosure.

Referring to FIGS. 2 a and 2 b , the light emitting element LD may further include at least one electrode layer 14 disposed on one end of the second conductive semiconductor layer 13.

Referring to FIGS. 3 a and 3 b , the light emitting element LD may further include at least one electrode layer 15 disposed on one end of the first conductive semiconductor layer 11.

Each of the electrode layers 14 and 15 may be an ohmic contact electrode, but it is not limited thereto. Furthermore, each of the electrode layers 14 and 15 may include metal or conductive metal oxide. For example, each of the electrode layers 14 and 15 may be formed of transparent electrode materials such as chromium (Cr), titanium (Ti), aluminum (Al), gold (Au), nickel (Ni), oxides or alloys thereof, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO) alone or in combination. The electrode layers 14 and 15 may be substantially transparent or semitransparent. Thereby, light generated from the light emitting element LD may be emitted to the outside after passing through the electrode layers 14 and 15.

In an embodiment, the insulating film INF may at least partially enclose the outer surfaces of the electrode layers 14 and 15, or may not enclose them. In other words, the insulating film INF may be selectively formed on the surfaces of the electrode layers 14 and 15. Furthermore, the insulating film INF may be formed to expose the opposite ends of the light emitting element LD that have different polarities, for example, may expose at least one area of each of the electrode layers 14 and 15. However, the present disclosure is not limited thereto, and the insulating film INF may not be provided.

If the insulating film INF is provided on the surface of the light emitting element LD, for example, on the surface of the active layer 12, the active layer 12 may be prevented from short-circuiting with at least one electrode, e.g., at least one contact electrode of contact electrodes connected to the opposite ends of the light emitting element LD, etc. Consequently, the electrical stability of the light emitting element LD may be secured.

Furthermore, the insulating film INF may be formed on the surface of the light emitting element LD, thus minimizing surface defects of the light emitting element LD and improving the lifespan and efficiency of the light emitting element LD. Moreover, the insulating film INF may be formed on the light emitting element LD, thus preventing an undesired short circuit between the light emitting elements LD from occurring even if multiple light emitting elements LD are arranged in close proximity to each other.

In an embodiment, the light emitting element LD may be manufactured through a surface treatment process (e.g., coating). For example, when the plurality of light emitting elements LD are mixed with fluid solution (or solvent) to be supplied to each light emitting area (e.g., light emitting area of each pixel), the light emitting elements LD may be uniformly dispersed without being non-uniformly aggregated in the solution. Here, the light emitting area is an area in which light is emitted by the light emitting elements LD. The light emitting area may be distinguished from a non-emission area in which light is not emitted.

In some embodiments, the insulating film INF itself may be formed of a hydrophobic film using hydrophobic material, or an additional hydrophobic film formed of the hydrophobic material may be formed on the insulating film INF. In an embodiment, the hydrophobic material may be a material containing fluorine to exhibit hydrophobicity. In an embodiment, the hydrophobic material may be applied to the light emitting elements LD in the form of a self-assembled monolayer (SAM). In this case, the hydrophobic material may include octadecyl trichlorosilane, fluoroalkyl trichlorosilane, perfluoroalkyl triethoxysilane, etc. Furthermore, the hydrophobic material may be a commercially available fluorine containing material such as Teflon™ or Cytop™, or a corresponding material.

A light emitting device including the light emitting element LD described above may be used in various devices including a display device which requires a light source. For instance, at least one subminiature light emitting element LD, e.g., a plurality of subminiature light emitting elements LD each having a size ranging from the nanoscale to the microscale, may be disposed in each pixel area of the display panel to form a light source (or, a light source unit) of the corresponding pixel using the subminiature light emitting elements LD. Furthermore, the field of application of the light emitting element LD according to the present disclosure is not limited to a display device. For example, the light emitting element LD may also be used in other types of devices such as a lighting device, which requires a light source.

FIG. 4 is a plan view illustrating a display device in accordance with an embodiment of the present disclosure. In an embodiment, FIG. 4 illustrates a display device, particularly, a display panel PNL provided in the display device, as an example of a device which may use, as a light source, the light emitting elements LD described with reference to FIGS. 1 a to 3 b. In accordance with the embodiment, FIG. 4 simply illustrates the structure of the display panel PNL, focused on a display area DA. In some embodiments, although not illustrated, at least one driving circuit component (e.g., at least one of a scan driver and a data driver) and/or a plurality of lines may be further provided on the display panel PNL.

Referring to FIG. 4 , the display panel PNL may include a base layer (or substrate) SUB1, and a pixel PXL disposed on the base layer SUB1. In detail, the display panel PNL and the base layer SUB1 may include a display area DA configured to display an image, and a non-display area NDA other than the display area DA.

In an embodiment, the display area DA may be disposed in a central area of the display panel PNL, and the non-display area NDA may be disposed along a border of the display panel PNL in such a way as to enclose the display area DA. The locations of the display area DA and the non-display area NDA are not limited to this, and the locations thereof may be changed.

The base layer SUB1 may form a base of the display panel PNL. For example, the base layer SUB1 may form a base of a lower panel (e.g., a lower plate of the display panel PNL).

In an embodiment, the base layer SUB1 may be a rigid or flexible substrate, and the material or properties thereof are not particularly limited. For example, the base layer SUB1 may be a rigid substrate made of glass or reinforced glass, or a flexible substrate formed of a thin film made of plastic or metal. Furthermore, the base layer SUB1 may be a transparent substrate, but it is not limited thereto. For instance, the base layer SUB1 may be a translucent substrate, an opaque substrate, or a reflective substrate.

An area on the base layer SUB1 is defined as the display area DA in which the pixels PXL are disposed, and the other area thereof is defined as the non-display area NDA. For example, the base layer SUB1 may include the display area DA including a plurality of pixel areas on which the pixels PXL are formed, and the non-display area NDA disposed around the display area DA. Various lines and/or internal circuits which are connected to the pixels PXL of the display area DA may be disposed in the non-display area NDA.

The pixel PXL may include at least one light emitting element LD, e.g., at least one rod-type light emitting diode according to any one of embodiments shown in FIGS. 1 a to 3 b, which is driven by a corresponding scan signal and a corresponding data signal. For example, the pixel PXL may include a plurality of rod-type light emitting diodes, each of which has a small size ranging from the nanoscale to the microscale, and which are connected parallel to each other. The plurality of rod-type light emitting diodes may form a light source of the pixel PXL.

Furthermore, the pixel PXL may include a plurality of sub-pixels. For example, the pixel PXL may include a first sub-pixel SPX1, a second sub-pixel SPX2, and a third sub-pixel SPX3. In an embodiment, the first, second, and third sub-pixels SPX1, SPX2, and SPX3 may emit different colors of light. For instance, the first sub-pixel SPX1 may be a red sub-pixel for emitting red light, the second sub-pixel SPX2 may be a green sub-pixel for emitting green light, and the third sub-pixel SPX3 may be a blue sub-pixel for emitting blue light. However, the colors, types and/or number of sub-pixels forming each pixel PXL are not particularly limited. For example, the color of light which is emitted from each sub-pixel may be changed in various ways. Although in FIG. 4 there is illustrated an embodiment where the pixels PXL are arranged in the display area DA in a stripe shape, the present disclosure is not limited thereto. For example, the pixels PXL may be arranged in various pixel array forms that are known.

In embodiments, each of the sub-pixels SPX1, SPX2, and SPX3 may include a plurality of unit pixels.

FIG. 5 is a circuit diagram illustrating an example of a sub-pixel included in the display device of FIG. 4 . FIG. 5 illustrates the first to third sub-pixels SPX1, SPX2, and SPX3 included in the display device of FIG. 4 . Since the first to third sub-pixels SPX1, SPX2, and SPX3 are substantially equal to each other except that the first to third sub-pixels SPX1, SPX2, and SPX3 are connected to corresponding data lines Dj, Dj+1, and Dj+2, respectively, the first to third sub-pixels SPX1, SPX2, and SPX3 will be described based on the first sub-pixel SPX1.

The first to third sub-pixels SPX1, SPX2, and SPX3 may be disposed in areas, respectively, which are partitioned by scan lines Si−1 and Si (i is a positive integer) and data lines Dj, Dj+1, and Dj+2 (j is a positive integer). For example, the first sub-pixel SPX1 may be disposed in an area defined by i−1-th and i-th scan lines Si−1 and Si and j-th and j+1-th data lines Dj and Dj+1. However, the arrangement of the first to third sub-pixels SPX1, SPX2, and SPX3 is not limited thereto.

The first sub-pixel SPX1 may be connected to the scan line Si and the data line Dj, and also be connected to a first power line and a second power line. Here, a first power supply VDD may be applied to the first power line, and a second power supply VSS may be applied to the second power line. Each of the first and second power lines may be a common line connected to the plurality of sub-pixels. The first and second power supplies VDD and VSS may have different potentials to allow the first sub-pixel SPX1 to emit light. The first power supply VDD may have a voltage level higher than that of the second power supply VSS.

In embodiments, the first sub-pixel SPX1 may include at least one unit pixel SSPX1 to SSPXk (k is a natural number).

Each of the unit pixel SSPX1 to SSPXk may be connected to the scan line Si and the data line Dj, and also be connected to the first power line and the second power line. Each of the unit pixels SSPX1 to SSPXk may emit light having a luminance corresponding to a data signal transmitted through the data line Dj in response to a scan signal transmitted through the scan line Si. The unit pixels SSPX1 to SSPXk may include substantially the same pixel structure or pixel circuit.

In other words, the first sub-pixel SPX1 may include unit pixels SSPX1 to SSPXk that independently emit light, in response to one scan signal and one data signal.

In an embodiment, each of the unit pixels SSPX1 to SSPXk (or the sub-pixels SPX1 to SPX3) may be formed of an active pixel. However, the types, structures, and/or driving schemes of the unit pixels capable of being applied to the display device according to the present disclosure are not particularly limited. For example, the unit pixel may be formed of a pixel of the display device having various passive or active structures that are known.

FIGS. 6 a to 6 d are circuit diagrams illustrating an example of the unit pixel included in the sub-pixel of FIG. 5 .

The first to k-th unit pixels SSPX1 to SSPXk shown in FIG. 6 a may have a substantially identical or similar structure. The unit pixel SSPX shown in FIGS. 6 b to 6 d may be any one of the first to k-th unit pixels SSPX1 to SSPXk provided in the first sub-pixel SPX1 of FIG. 6 a . Therefore, in descriptions of FIGS. 6 a to 6 d , the first to k-th unit pixels SSPX1 to SSPXk will be collectively referred to as “unit pixel SSPX”.

First, referring to FIG. 6 a , the unit pixel SSPX may include a light source unit LSU that emits light having a luminance corresponding to a data signal. The unit pixel SSPX may selectively further include a pixel circuit PXC configured to drive the light source unit LSU.

In an embodiment, the light source unit LSU may include a plurality of light emitting elements LD that are electrically connected to each other between the first power supply VDD and the second power supply VSS. In an embodiment, the light emitting elements LD may be connected in parallel to each other, but the present disclosure is not limited thereto. For example, a plurality of light emitting elements LD may be connected in a serial/parallel combination structure between the first power supply VDD and the second power supply VSS.

The first and second power supplies VDD and VSS may have different potentials to allow the light emitting elements LD to emit light. For example, the first power supply VDD may be set as a high-potential power supply, and the second power supply VSS may be set as a low-potential power supply. Here, a difference in potential between the first and second power supplies VDD and VSS may be set to a threshold voltage of the light emitting elements LD or more at least during a light emitting period of the unit pixel SSPX (or first sub-pixel SPX1).

Although in FIG. 6 a there is illustrated an embodiment in which the light emitting elements LD are connected in parallel in the same direction (e.g., in a forward direction) between the first power supply VDD and the second power supply VSS, the present disclosure is not limited thereto. For example, some of the light emitting elements LD may be connected to each other in the forward direction between the first and second power supplies VDD and VSS, thus forming respective valid light sources, and the other light emitting elements LD may be connected to each other in the reverse direction. Alternatively, the unit pixel SSPX may include only a single light emitting element LD (e.g. a single valid light source connected in the forward direction between the first and second power supplies VDD and VSS).

According to an embodiment, one end of each of the light emitting elements LD may be connected in common to a corresponding pixel circuit PXC through a first electrode, and may be connected to the first power supply VDD through the pixel circuit PXC and the first power line. A remaining end of each of the light emitting elements LD may be connected in common to the second power supply VSS through a second electrode and the second power supply line.

The light source unit LSU may emit light having a luminance corresponding to driving current supplied thereto through the corresponding pixel circuit PXC. Hence, a predetermined image may be displayed on the display area DA (refer to FIG. 4 ).

The pixel circuit PXC may be connected to the scan line Si and the data line Dj of the corresponding sub-pixel (i.e. the first sub-pixel SPX1). For example, if the first sub-pixel SPX1 is disposed on an i-th row and a j-th column in the display area DA, the pixel circuit PXC of the unit pixel SSPX may be connected to the i-th scan line Si and the j-th data line Dj of the display area DA.

The pixel circuit PXC may include first and second transistors T1 and T2, and a storage capacitor Cst.

The first transistor (or driving transistor) T1 may be connected between the first power supply VDD and the light source unit LSU. A gate electrode of the first transistor T1 may be connected to a first node N1. The first transistor T1 may control driving current to be supplied to the light source unit LSU in response to a voltage of the first node N1.

The second transistor (or switching transistor) T2 may be connected between the data line Dj and the first node N1. A gate electrode of the second transistor T2 may be connected to the scan line Si.

In response to a scan signal of a gate-on voltage (e.g., a low voltage) supplied from the scan line Si, the second transistor T2 may be turned on to electrically connect the first node N1 to the data line Dj.

During each frame period, a data signal of a corresponding frame may be supplied to the data line Dj. The data signal may be transmitted to the first node N1 via the second transistor T2. Thereby, a voltage corresponding to the data signal may be charged to the storage capacitor Cst.

A first electrode of the storage capacitor Cst may be connected to the first power supply VDD, and a second electrode thereof may be connected to the first node N1. The storage capacitor Cst may charge a voltage corresponding to a data signal supplied to the first node N1 during each frame period, and maintain the charged voltage until a data signal of a subsequent frame is supplied.

Although FIG. 6 a illustrates that all of the transistors, e.g., the first and second transistors T1 and T2, included in the pixel circuit PXC are formed of P-type transistors, the present disclosure is not limited to this. For example, at least one of the first and second transistors T1 and T2 may be changed to an N-type transistor.

For instance, as shown in FIG. 6 b , both the first and second transistors T1 and T2 may be formed of N-type transistors. In this case, during each frame period, a gate-on voltage of a scan signal for writing a data signal supplied to the data line Dj in the unit pixel SSPX may be a high level voltage. Likewise, a voltage of a data signal for turning on the first transistor T1 may be a voltage having a waveform opposite to that of the embodiment of FIG. 6 a . For example, in the embodiment of FIG. 6 b , as a gray scale value to be expressed increases, the voltage level of a data signal to be supplied may increase.

The unit pixel SSPX illustrated in FIG. 6 b is substantially similar in configuration and operation to the unit pixel SSPX of FIG. 6 a , except that the connection positions of some circuit elements and the voltage levels of control signals (e.g., a scan signal and a data signal) are changed depending on a change in type of the transistor. Therefore, detailed descriptions of the unit pixel SSPX of FIG. 6 b will be omitted.

The structure of the pixel circuit PXC is not limited to the embodiments illustrated in FIGS. 6 a and 6 b . In other words, the pixel circuit PXC may be formed of a well-known pixel circuit which may have various structures and/or be operated by various driving schemes. For example, the pixel circuit PXC may be configured in the same manner as that of an embodiment illustrated in FIG. 6 c.

Referring to FIG. 6 c , the pixel circuit PXC may be connected not only to a corresponding scan line Si but also to at least another scan line (or a control line). For example, the pixel circuit PXC of the sub-pixel SPX (or the unit pixel SSPX included therein) disposed on the i-th row in the display area DA may be further connected to an i−1-th scan line Si−1 and/or an i+1-th scan line Si+1. In an embodiment, the pixel circuit PXC may be connected not only to the first and second power supplies VDD and VSS but also to other power supplies. For example, the pixel circuit PXC may also be connected to an initialization power supply Vint.

In an embodiment, the pixel circuit PXC may include first to seventh transistors T1 to T7 and a storage capacitor Cst.

The first transistor T1 may be connected between the first power supply VDD and the light source unit LSU. A first electrode (e.g., a source electrode) of the first transistor T1 may be connected to the first power supply VDD through the fifth transistor T5, and a second electrode (e.g., a drain electrode) of the first transistor T1 may be connected via the sixth transistor T6 to one electrode of the light source unit LSU (e.g., the first electrode of the corresponding sub-pixel SPX). A gate electrode of the first transistor T1 may be connected to the first node N1. The first transistor T1 may control driving current to be supplied to the light source unit LSU in response to a voltage of the first node N1.

The second transistor T2 may be connected between the data line Dj and the first electrode of the first transistor T1. A gate electrode of the second transistor T2 may be connected to the corresponding scan line Si. When a scan signal having a gate-on voltage is supplied from the scan line Si, the second transistor T2 may be turned on to electrically connect the data line Dj to the first electrode of the first transistor T1. Hence, if the second transistor T2 is turned on, a data signal supplied from the data line Dj may be transmitted to the first transistor T1.

The third transistor T3 may be connected between the second electrode (e.g., the drain electrode) of the first transistor T1 and the first node N1. A gate electrode of the third transistor T3 may be connected to the corresponding scan line Si. When a scan signal of a gate-on voltage is supplied from the scan line Si, the third transistor T3 may be turned on to connect the first transistor T1 in the form of a diode.

The fourth transistor T4 may be connected between the first node N1 and an initialization power supply Vint. A gate electrode of the fourth transistor T4 may be connected to a previous scan line, e.g., an i−1-th scan line Si−1. When a scan signal of a gate-on voltage is supplied to the i−1-th scan line Si−1, the fourth transistor T4 may be turned on so that the voltage of the initialization power supply Vint may be transmitted to the first node N1. Here, the voltage of the initialization power supply Vint may be a minimum voltage of a data signal or less.

The fifth transistor T5 may be connected between the first power supply VDD and the first transistor T1. A gate electrode of the fifth transistor T5 may be connected to a corresponding emission control line, e.g., an i-th emission control line Ei. The fifth transistor T5 may be turned off when an emission control signal having a gate-off voltage (e.g., a high voltage) is supplied to the emission control line Ei, and may be turned on in other cases.

The sixth transistor T6 may be connected between the first transistor T1 and the first electrode of the light source unit LSU. A gate electrode of the sixth transistor T6 may be connected to a corresponding emission control line, e.g., the i-th emission control line Ei. The sixth transistor T6 may be turned off when an emission control signal of a gate-off voltage is supplied to the emission control line Ei, and may be turned on in other cases.

The seventh transistor T7 may be connected between the first electrode of the light source unit LSU and the initialization power supply Vint (or a third power line configured to transmit initialization power). A gate electrode of the seventh transistor T7 may be connected to any one of scan lines of a subsequent stage, e.g., to the i+1-th scan line Si+1. When a scan signal of a gate-on voltage is supplied to the i+1-th scan line Si+1, the seventh transistor T7 may be turned on so that the voltage of the initialization power supply Vint may be supplied to the first electrode of the light source unit LSU. In this case, during each initialization period in which the voltage of the initialization power supply Vint is transmitted to the light source unit LSU, the voltage of the first electrode of the light source unit LSU may be initialized.

The control signal for controlling the operation of the seventh transistor T7 may be variously changed. For example, the gate electrode of the seventh transistor T7 may be connected to a scan line of a corresponding horizontal line, i.e., an i-th scan line Si. In this case, when a scan signal having a gate-on voltage is supplied to the i-th scan line Si, the seventh transistor T7 may be turned on so that the voltage of the initialization power supply Vint may be supplied to the first electrode of the light source unit LSU.

The storage capacitor Cst may be connected between the first power supply VDD and the first node N1. The storage capacitor Cst may store a voltage corresponding both to the data signal applied to the first node N1 during each frame period and to the threshold voltage of the first transistor T1.

Although FIG. 6 c illustrates that the transistors included in the pixel circuit PXC, e.g., the first to seventh transistors T1 to T7, are formed of P-type transistors, the present disclosure is not limited to this. For example, at least one of the first to seventh transistors T1 to T7 may be changed to an N-type transistor.

In an embodiment, the pixel circuit PXC may be further connected to another line as well as the data line Dj.

Referring to FIG. 6 d , the pixel circuit PXC may be connected to a sensing line SENj. The pixel circuit PXC may include first to third transistors T1 to T3, and a storage capacitor Cst. Since the first and second transistors T1 and T2 and the storage capacitor Cst are substantially equal or similar to the first and second transistors T1 and T2 and the storage capacitor Cst described with reference to FIG. 6 b , repetitive explanation thereof will be omitted.

The third transistor T3 may be connected between the sensing line SENj and the second node N2. The gate electrode of the third transistor T3 may be connected to the first scan line S1 and a second scan line S2 (e.g., a j-th scan line Sj and a j+1-th scan line Sj+1).

The light source unit LSU may be connected between the second node N2 and the second power supply line (i.e., the power supply line to which the second power supply VSS is applied).

The third transistor T3 may be turned on in response to the scan signal of the gate-on voltage transmitted from the second scan line S2 to electrically connect the sensing line SENj to the second node N2.

For example, in case that the third transistor T3 is turned on with driving current corresponding to reference voltage flowing in the first transistor T1, the driving current flowing through the first transistor T1 may be provided to an external sensing device through the third transistor T3 and the sensing line SENj, and a signal corresponding to the characteristics of the first transistor T1 (e.g., Vth) based on the driving current may be output through the sensing line SENj to an external device.

Furthermore, the structure of the unit pixel SSPX which may be applied to the present disclosure is not limited to the embodiments shown in FIGS. 6 a to 6 d , and the unit pixel SSPX may have various well-known structures. For example, the pixel circuit PXC included in the unit pixel SSPX may be formed of a well-known pixel circuit which may have various structures and/or be operated by various driving schemes. The unit pixel SSPX may be formed in a passive light emitting display panel or the like. In this case, the pixel circuit PXC may be omitted, and each of the first and second electrodes of the light source unit LSU may be directly connected to the scan line Si, the data line Dj, a power line, and/or the control line.

FIG. 7 is a plan view illustrating an example of sub-pixels included in the display device of FIG. 4 . FIG. 8 is a plan view illustrating an example of a first sub-pixel of the sub-pixels of FIG. 7 . FIG. 7 illustrates the structure of sub-pixels SPX1 to SPX3 based on a light source unit LSU (refer to FIGS. 6 a to 6 d ) (or a light emitting element layer) included in the sub-pixels SPX1 to SPX3. Since the first to third sub-pixels SPX1 to SPX3 are substantially equal to each other, the light source unit LSU will be described based on the first sub-pixel SPX1. Furthermore, unit pixels in each sub-pixel may receive the same electrical signal. Therefore, in the present embodiment, there will be described an example in which each of the sub-pixels includes one unit pixel.

Referring to FIGS. 7 and 8 , the first sub-pixel SPX1 may include a first electrode ELT1 and a second electrode ELT2 disposed at positions spaced apart from each other in the first sub-pixel area SPA1, and at least one light emitting element LD connected between the first and second electrodes ELT1 and ELT2.

In an embodiment, the first, second, and third light emitting elements LD1, LD2, and LD3 included in each of the first to third sub-pixels SPX1 to SPX3 may emit light having the same color or different colors. For example, each first light emitting element LD1 may be a red light emitting diode configured to emit red light. Each second light emitting element LD2 may be a green light emitting diode configured to emit green light. Each third light emitting element LD3 may be a blue light emitting diode configured to emit blue light.

For example, all of the first, second, and third light emitting elements LD1, LD2, and LD3 may be formed of blue light emitting diodes configured to emit blue light. In this case, in order to form a full-color pixel PXL, a light conversion layer and/or a color filter for converting the color of light emitted from the corresponding sub-pixel SPX may be disposed on at least some of the first to third sub-pixels SPX1, SPX2, and SPX3.

In an embodiment, the first electrode ELT1 and the second electrode ELT2 may be disposed at positions spaced apart from each other in the first sub-pixel area SPA1 such that at least some areas thereof face each other. For example, the first and second electrodes ELT1 and ELT2 may generally extend in a first direction DR1, and be spaced apart from each other by a predetermined distance and disposed in parallel to each other.

In embodiments, one emission area may be defined by each sub-pixel area. The light emitting area may be distinguished by the non-light-emitting area. Although not clearly illustrated, a pixel defining layer (or a bank, a light block pattern) for preventing light emitted from the light emitting element LD from being transmitted to another area may be disposed in the non-light-emitting area to overlap therewith.

In an embodiment, the first electrode ELT1 may be connected to a first connection electrode CNL1. The first electrode ELT1 may be integrally connected to the first connection electrode CNL1. For example, the first electrode ELT1 may be formed of at least one branch diverging from the first connection electrode CNL1. In other words, the first electrode ELT1 may extend from the first connection electrode CNL1 (or a first connection line). In case that the first electrode ELT1 and the first connection electrode CNL1 are formed integrally with each other, the first connection electrode CNL1 may be regarded as one area of the first electrode ELT1. However, the present disclosure is not limited thereto.

The first connection electrode CNL1 may be connected to the first power line (i.e., the power line to which the first power supply VDD is applied) that is described with reference to FIGS. 6 a, 6 c , and 6 d.

In an embodiment, the second electrode ELT2 may be connected to a second connection electrode CNL2. The second electrode ELT2 may be integrally connected to the second connection electrode CNL2. For example, the second electrode ELT2 may be formed of at least one branch diverging from the second connection electrode CNL2. In other words, the second electrode ELT2 may extend from the second connection electrode CNL2 (or a second connection line) extending in a second direction DR2. In case that the second electrode ELT2 and the second connection electrode CNL2 are formed integrally with each other, the second connection electrode CNL2 may be regarded as one area of the second electrode ELT2.

The second connection electrode CNL2 may be connected to the second power line (i.e., the power line to which the second power supply VSS is applied) that is described with reference to FIGS. 6 a, 6 c , and 6 d.

The first connection electrode CNL1 and the second connection electrode CNL2 may be spaced apart from each other by a predetermined distance. The first electrode ELT1 and the second electrode ELT2 may be formed between the first connection electrode CNL1 and the second connection electrode CNL2.

The first connection electrode CNL1 may be connected to the pixel circuit PXC (or the first transistor T1). For example, the first connection electrode CNL1 may be connected to the pixel circuit PXC (or the first transistor T1) through a contact hole CH.

In an embodiment, each of the first and second electrodes ELT1 and ELT2 may have a single-layer or multi-layer structure. Although not clearly illustrated, the first electrode ELT1 may have a multi-layer structure including a first reflective electrode and a first conductive capping layer, and the second electrode may have a multi-layer structure including a second reflective electrode and a second conductive capping layer.

The first electrode ELT1 and the second electrode ELT2 each may have a bent shape. For example, if the first connection electrode CNL1 and the second electrode CNL2 each have a shape extending in the first direction DR1, the first electrode ELT1 and the second electrode ELT2 may generally extend in the second direction DR2 intersecting the first direction DR1 and be bent in the first direction. The first electrode ELT1 and the second electrode ELT2 each may have a curved shape (e.g., a ‘U’ shaped or ‘S’ shape) or a zigzag shape (e.g., a ‘V’ shape or ‘W’ shape). In other words, rather than having a linear shape extending in only one direction (e.g., the second direction DR2), each of the first electrode ELT1 and the second electrode ELT2 may generally extend in only one direction (e.g., the second direction DR2) and have a bent portion which protrudes from at least a portion thereof in a direction (e.g., the first direction DR1) intersecting the extension direction. The bent portion may be formed of a curved line, or formed of a combination of linear lines extending in two different directions.

However, the present disclosure is not limited thereto. For example, the shapes and/or mutual arrangement relationship of the first and second electrodes ELT1 and ELT2 may be changed in various ways.

Referring to FIG. 8 , a first partition wall PW1 may be disposed under the first electrode ELT1 and overlap one area of the first electrode ELT1. A second partition wall PW2 may be disposed under the second electrode ELT2 and overlap one area of the second electrode ELT2. The first and second partition walls PW1 and PW2 may be disposed in the emission area EMA at positions spaced apart from each other, and make areas of the first and second electrode ELT1 and ELT2 protrude upward. For example, the first electrode ELT1 may be disposed on the first partition wall PW1 and protrude in a height direction (or a thickness direction) of the base layer SUB1 by the first partition wall PW1. The second electrode ELT2 may be disposed on the second partition wall PW2 and protrude in the height direction of the base layer SUB1 by the second partition wall PW2. The first partition wall PW1 and the second partition wall PW2 may also include bent portions corresponding to the shapes of the first electrode ELT1 and the second electrode ELT2 that overlap the first and second partitions walls PW1 and PW2.

In an embodiment, at least one light emitting element LD, e.g., a plurality of light emitting elements LD, may be arranged between the first and second electrodes ELT1 and ELT2. A plurality of light emitting elements LD may be connected in parallel to each other in the emission area EMA in which the first electrode ELT1 and the second electrode ELT2 are disposed to face each other.

Although FIG. 8 illustrates that the light emitting elements LD are aligned in a normal direction with respect to the direction in which the first and the second electrodes ELT1 and ELT2 extend (the longitudinal direction of the light emitting elements LD are aligned in the normal direction with respect to the direction in which the first and second electrodes ELT1 and ELT2 extend), the alignment direction of the light emitting elements LD is not limited thereto. For example, at least one of the light emitting elements LD may be aligned in diagonal direction with respect to the extension direction of the first and second electrodes ELT1 and ELT2 and the normal direction.

Each of the light emitting elements LD may be electrically connected between the first electrode ELT1 and the second electrode ELT2. For example, the respective first ends EP1 of the light emitting elements LD may be electrically connected to the first electrode ELT1. The respective second ends EP2 of the light emitting elements LD may be electrically connected to the second electrode ELT2.

In an embodiment, the first end of each of the light emitting elements LD may be electrically connected to the first electrode ELT1 through at least one contact electrode, e.g., a first contact electrode CNE1, rather than being directly disposed on the first electrode ELT1. However, the present disclosure is not limited thereto. For example, in an embodiment of the present disclosure, the first ends of the light emitting elements LD may directly contact the first electrode ELT1 and be electrically connected to the first electrode ELT1.

Likewise, the second end of each of the light emitting elements LD may be electrically connected to the second electrode ELT2 through at least one contact electrode, e.g., a second contact electrode CNE2, rather than being directly disposed on the second electrode ELT2. However, the present disclosure is not limited thereto. For example, in an embodiment of the present disclosure, the second end of each of the light emitting elements LD may directly contact the second electrode ELT2 and be electrically connected to the second electrode ELT2.

In an embodiment, each of the light emitting elements LD may be formed of a light emitting diode which is made of material having an inorganic crystal structure and has a subminiature size, e.g., ranging from the nanoscale to the microscale. For example, each of the light emitting elements LD may be a subminiature light emitting diode having a size ranging from the nanoscale to the microscale, as illustrated in any one of FIGS. 1 a to 3 b. However, the type of light emitting elements LD which may be applied to the present disclosure is not limited thereto. For example, the light emitting element LD may be formed by a growth scheme and, e.g., be a light emitting diode having a core-shell structure having a size ranging from the nanoscale to the microscale.

In an embodiment, the light emitting elements LD may be prepared in a diffused form in a predetermined solution, and then supplied to the emission area EMA of each sub-pixel SPX by an inkjet printing scheme or a slit coating scheme. Furthermore, the light emitting elements LD may be simultaneously supplied into the emission area EMA. For example, the light emitting elements LD may be mixed with a volatile solvent and supplied to the emission area EMA. Here, if a predetermined voltage is supplied to the first and second electrodes ELT1 and ELT2 of the sub-pixel SPX, an electric field is formed between the first and second electrodes ELT1 and ELT2, whereby the light emitting elements LD are self-aligned between the first and second electrodes ELT1 and ELT2. After the light emitting elements LD have been aligned, the solvent may be removed by a volatilization scheme or other schemes. In this way, the light emitting elements LD may be reliably arranged between the first and second electrodes ELT1 and ELT2. Furthermore, since the first contact electrode CNE1 and the second contact electrode CNE2 are formed on the first ends and the second ends of the light emitting elements LD, the light emitting elements LD may be reliably connected between the first and second electrodes ELT1 and ELT2.

Since a separate circuit element, a line, or the like is not disposed between the first and second electrodes ELT1 and ELT2 and the base layer SUB1, interference resulting from a circuit element, a conductive pattern, etc. may be prevented from occurring at the step of forming the electric field between the first and second electrodes ELT1 and ELT2. Consequently, the efficiency of alignment of the light emitting elements LD may be enhanced.

In an embodiment, the first contact electrode CNE1 may be formed on the first ends of the light emitting elements LD and at least one area of the first electrode ELT1 corresponding to the first ends, whereby the first ends of the light emitting elements LD may be physically and/or electrically connected to the first electrode ELT1. Likewise, the second contact electrode CNE2 may be formed on the second ends EP2 of the light emitting elements LD and at least one area of the second electrode ELT2 corresponding to the second ends, whereby the second ends of the light emitting elements LD may be physically and/or electrically connected to the second electrode ELT2.

The light emitting elements LD disposed in the emission area EMA may be grouped to form a light source of the corresponding unit pixel (and the sub-pixel SPX). If driving current flows through at least one sub-pixel SPX during each frame period, the light emitting elements LD that are connected in the forward direction between the first and second electrodes ELT1 and ELT2 of the sub-pixel SPX may emit light having a luminance corresponding to the driving current.

Light emitted from each light emitting element LD may have directionality. The first and second electrodes ELT1 and ELT2 may have bent portions rather than extending in only one direction. Hence, the light emitting elements LD that are aligned in the normal direction with respect to the direction in which the first and second electrodes ELT1 and ELT2 extend may be oriented in various directions depending on aligned positions. Consequently, the viewing angle of the display device may be improved.

FIGS. 9 a to 9 d are sectional views illustrating examples of the unit pixel, taken along line I-I′ of FIG. 8 . FIGS. 9 a to 9 d each illustrates any one sub-pixel area SPA (e.g., the first sub-pixel area SPA1) formed in the display panel PNL. In an embodiment, the cross-sectional structures of the first, second, and third sub-pixels SPX1, SPX2, and SPX3 described above may be substantially identical or similar to each other. Therefore, for the sake of explanation, in FIGS. 9 a to 9 d , the structures of the first, second, and third sub-pixels SPX1, SPX2, and SPX3 will be collectively described based on the first sub-pixel SPX1.

Referring to FIG. 9 a , the pixel circuit layer PCL and the display element layer LDL may be successively disposed in each sub-pixel area SPA on the base layer SUB1. In an embodiment, the pixel circuit layer PCL and the display element layer LDL may be formed in the entirety of the display area DA of the display panel PNL.

In an embodiment, the pixel circuit layer PCL may include circuit elements which constitute the pixel circuits PXC of the sub-pixels SPX. The display element layer LDL may include light emitting elements LD of the sub-pixels SPX (or the unit pixels SSPX).

For example, in the first sub-pixel area SPA1 on the base layer SUB1, the pixel circuit layer PCL including circuit elements constituting the pixel circuit PXC of the corresponding first sub-pixel SPX1, and the display element layer LDL including at least one light emitting element LD, e.g., a plurality of first light emitting elements LD1, provided in the first sub-pixel SPX1 may be successively disposed on one surface of the base layer SUB1.

In an embodiment, the pixel circuit layer PCL may include a plurality of circuit elements which are formed in the first sub-pixel area SPA1 and form the pixel circuit PXC of the first sub-pixel SPX1 (or the first unit pixel SSPX1). For example, the pixel circuit layer PCL may include a plurality of transistors disposed in the first sub-pixel area SPA1, e.g., the first and second transistors T1 and T2 of FIG. 6 a . Although not illustrated in FIG. 9 a , the pixel circuit layer PCL may include a storage capacitor Cst disposed in the sub-pixel area SPA, various signal lines (e.g., the scan line Si and the data line Dj illustrated in FIG. 5 ) connected to the pixel circuit PXC, and various power lines (e.g., a first power line (not illustrated) and a second power line PL configured to respectively transmit a voltage of the first power supply VDD and a voltage of the second power supply VSS) connected to the pixel circuit PXC and/or the light emitting elements LD.

In an embodiment, a plurality of transistors, e.g., first and second transistors T1 and T2, provided in the pixel circuit PXC may have a substantially identical or similar cross-sectional structure. However, the present disclosure is not limited thereto. In an embodiment, at least some of the plurality of transistors may have different types and/or structures.

In addition, the pixel circuit layer PCL may include a plurality of insulating layers. For example, the pixel circuit layer PCL may include a buffer layer BFL, a gate insulating layer GI, an interlayer insulating layer ILD, and a passivation layer PSV which are successively stacked on one surface of the base layer SUB1.

In an embodiment, the buffer layer BFL may prevent impurities from diffusing into the circuit elements. The buffer layer BFL may be formed of a single layer, or may be formed of multiple layers having at least double or more layers. In the case where the buffer layer BFL has a multi-layer structure, the respective layers may be formed of the same material or different materials. In an embodiment, the buffer layer BFL may be omitted.

In an embodiment, each of the first and second transistors T1 and T2 may include a semiconductor layer SCL, a gate electrode GE, a first transistor electrode ET1, and a second transistor electrode ET2. Although FIG. 9 a illustrates that each of the first and second transistors T1 and T2 includes the first transistor electrode ET1 and the second transistor electrode ET2 that are formed separately from the semiconductor layer SCL, the present disclosure is not limited thereto. For example, in an embodiment of the present disclosure, the first and/or second electrode ET1 and/or ET2 provided in at least one transistor disposed in each sub-pixel area SPA may be integrally formed with the corresponding semiconductor layer SCL.

The semiconductor layer SCL may be disposed on the buffer layer BFL. For example, the semiconductor layer SCL may be disposed between the gate insulating layer GI and the base layer SUB1 on which the buffer layer BFL is formed. The semiconductor layer SCL may include a first area which contacts a first transistor electrode ET1, a second area which comes into contact with a second transistor electrode ET2, and a channel area disposed between the first and second areas. In an embodiment, one of the first and second areas may be a source area, and the other may be a drain area.

In an embodiment, the semiconductor layer SCL may be a semiconductor pattern formed of polysilicon, amorphous silicon, an oxide semiconductor, etc. The channel area of the semiconductor layer SCL may be an intrinsic semiconductor, which is an undoped semiconductor pattern. Each of the first and second areas of the semiconductor layer SCL may be a semiconductor pattern doped with a predetermined impurity.

The gate electrode GE may be disposed on the semiconductor layer SCL with the gate insulating layer GI interposed therebetween. For example, the gate electrode GE may be disposed between the gate insulating layer GI and the interlayer insulating layer ILD and overlap at least one area of the semiconductor layer SCL.

The first and second transistor electrodes ET1 and ET2 may be disposed over the semiconductor layer SCL and the gate electrode GE with at least one interlayer insulating layer ILD interposed therebetween. For example, the first and second transistor electrodes ET1 and ET2 may be disposed between the interlayer insulating layer ILD and the passivation layer PSV. The first and second transistor electrodes ET1 and ET2 may be electrically connected to the semiconductor layer SCL. For example, the first and second transistor electrodes ET1 and ET2 may be respectively connected to the first area and the second area of the semiconductor layer SCL through contact holes which pass through the gate insulating layer GI and the interlayer insulating layer ILD.

In an embodiment, any one of the first and second transistor electrodes ET1 and ET2 of at least one transistor (e.g., the first transistor T1 shown in FIG. 6 a ) provided on the pixel circuit PXC may be electrically connected, through a contact hole CH passing through the passivation layer PSV, to the first electrode ELT1 of the light source unit LSU disposed over the passivation layer PSV.

Although not illustrated, in an embodiment, at least one signal line and/or power line that is connected to the sub-pixel SPX may be disposed on the same layer as that of one electrode of each of the circuit elements that form the pixel circuit PXC. For example, the second power line PL may be disposed on the same layer as that of the gate electrode GE of each of the first and second transistors T1 and T2. However, the structures and/or positions of the second power line PL, etc. may be changed in various ways.

The display element layer LDL may include first and second partition walls PW1 and PW2, first and second electrodes ELT1 and ELT2, a first insulating layer INS1, light emitting elements LD, a second insulating layer INS2, first and second contact electrodes CNE1 and CNE2, and a third insulating layer INS3, which are successively disposed and/or formed on the pixel circuit layer PCL.

The first and second partition walls PW1 and PW2 may be disposed on the pixel circuit layer PCL. The first and second partition walls PW1 and PW2 may be disposed at positions spaced apart from each other in the emission area EMA. The first and second partition walls PW1 and PW2 may protrude in a height direction on the pixel circuit layer PCL. In an embodiment, the first and second partition walls PW1 and PW2 may have substantially the same height, but the present disclosure is not limited thereto.

In an embodiment, the first partition wall PW1 may be disposed between the pixel circuit layer PCL and the first electrode ELT1. The first partition wall PW1 may be disposed adjacent to the first ends EP1 of the light emitting elements LD. For example, one sidewall of the first partition wall PW1 may be positioned adjacent to the first ends EP1 of the light emitting elements LD and disposed to face the first ends EP1.

In an embodiment, the second partition wall PW2 may be disposed between the pixel circuit layer PCL and the second electrode ELT2. The second partition wall PW2 may be disposed adjacent to the second ends EP2 of the light emitting elements LD. For example, one sidewall of the second partition wall PW2 may be positioned adjacent to the second ends EP2 of the light emitting elements LD and disposed to face the second ends EP2.

In an embodiment, each of the first and second partition walls PW1 and PW2 may have various shapes. For example, as illustrated in FIG. 9 a , each of the first and second partition walls PW1 and PW2 may have a cross-sectional shape of a trapezoid that is reduced in width from a bottom to a top thereof. In this case, each of the first and second partition walls PW1 and PW2 may have an inclined surface on at least one side. Alternatively, as illustrated in FIG. 9 b , each of the first and second partition walls PW1 and PW2 may have a semicircular or a semielliptical cross-section that is reduced in width from a bottom to a top thereof. In this case, each of the first and second partition walls PW1 and PW2 may have a curved surface on at least one side. In other words, the shape of each of the first and second partition walls PW1 and PW2 may be changed in various ways rather than being particularly limited. In an embodiment, at least one of the first and second partition walls PW1 and PW2 may be omitted or changed in position.

Each of the first and second partition walls PW1 and PW2 may include insulating material having inorganic material and/or organic material. For example, the first and second partition walls PW1 and PW2 may include at least one inorganic layer including various inorganic insulating materials that are known to those skilled in the art, such as SiNx or SiOx. Alternatively, the first and second partition walls PW1 and PW2 may include at least one organic layer and/or photoresist layer containing various known organic insulating materials, or may form a single- or multi-layer insulator containing organic/inorganic materials in combination. In other words, the constituent materials of the first and second partition walls PW1 and PW2 may be variously changed.

In an embodiment, each of the first and second partition walls PW1 and PW2 may function as a reflective member. For example, the first and second partition walls PW1 and PW2, along with the first and second electrodes ELT1 and ELT2 provided thereon, may function as reflectors that guide light emitted from each light emitting element LD in a desired direction, thus enhancing the light efficiency of the pixel PXL.

The first and second electrodes ELT1 and ELT2 may be respectively disposed over the first and second partition walls PW1 and PW2. The first and second electrodes ELT1 and ELT2 may be disposed at positions spaced apart from each other in the emission area EMA.

In an embodiment, the first and second electrodes ELT1 and ELT2 that are respectively disposed over the first and second partition walls PW1 and PW2 may have shapes corresponding to the respective shapes of the first and second partition walls PW1 and PW2. For example, the first and second electrodes ELT1 and ELT2 may have inclined surfaces or curved surfaces corresponding to the first and second partition walls PW1 and PW2, respectively, and protrude in a height direction (or a thickness direction) of the display element layer LDL.

Each of the first and second electrodes ELT1 and ELT2 may include at least one conductive material. For example, each of the first and second electrodes ELT1 and ELT2 may include at least one of metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Ti or an alloy thereof, conductive oxide such as ITO, IZO, ZnO, or ITZO, and a conductive polymer such as PEDOT; however, it is not limited thereto.

Each of the first and second electrodes ELT1 and ELT2 may have a single-layer or multi-layer structure. For example, each of the first and second electrodes ELT1 and ELT2 may include at least one reflective electrode layer. Each of the first and second electrodes ELT1 and ELT2 may selectively further include at least one of at least one transparent electrode layer disposed on an upper portion and/or a lower portion of the reflective electrode layer, and at least one conductive capping layer which covers an upper portion of the reflective electrode layer and/or the transparent electrode layer.

In an embodiment, the reflective electrode layer of each of the first and second electrodes ELT1 and ELT2 may be formed of conductive material having a uniform reflectivity. For example, the reflective electrode layer may include at least one of metals such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and an alloy thereof; however, the present disclosure is not limited thereto. In other words, reflective electrode layer may be formed of various reflective conductive materials. Each of the first and second electrodes ELT1 and ELT2 that includes the reflective electrode layer may enable light emitted from the opposite ends of each of the light emitting elements LD, i.e., the first and second ends EP1 and EP2, to more reliably travel in a direction (e.g., in a frontal direction) in which an image is displayed. Particularly, if the first and second electrodes ELT1 and ELT2 respectively have inclined or curved surfaces corresponding to the shapes of the first and second partition walls PW1 and PW2 and are respectively disposed to face the first and second ends EP1 and EP2 of the light emitting elements LD, light emitted from the first and second ends EP1 and EP2 of each light emitting elements LD may be reflected by the first and second electrodes ELT1 and ELT2 and thus more reliably travel in the frontal direction of the display panel PNL (e.g., in an upward direction of the base layer SUB1). Consequently, the efficiency of light emitted from the light emitting elements LD may be enhanced.

Furthermore, the transparent electrode layer of each of the first and second electrodes ELT1 and ELT2 may be formed of various transparent electrode materials. For example, the transparent electrode layer may include ITO, IZO or ITZO, but the present disclosure is not limited thereto. In an embodiment, each of the first and second electrodes ELT1 and ELT2 may have a triple-layer structure having a stacked structure of ITO/Ag/ITO. As such, if the first and second electrodes ELT1 and ELT2 each are formed of a multilayer structure of at least double or more layers, voltage drop due to signal delay (RC delay) may be minimized. Thus, a desired voltage can be effectively transmitted to the light emitting elements LD.

In addition, if each of the first and second electrodes ELT1 and ELT2 includes the conductive capping layer that covers the reflective electrode layer and/or the transparent electrode layer, it is possible to prevent the reflective electrode layer of the first and second electrodes ELT1 and ELT2 from being damaged due to defects caused during a process of manufacturing the pixel PXL. However, the conductive capping layer may be selectively included in the first and second electrodes ELT1 and ELT2, and may be omitted depending on embodiments. Furthermore, the conductive capping layer may be considered as a component of each of the first and second electrodes ELT1 and ELT2, or considered as a separate component disposed on the first and second electrodes ELT1 and ELT2.

The first insulating layer INS1 may be disposed on one area of each of the first and second electrode ELT1 and ELT2. For example, the first insulating layer INS1 may be formed to cover one area of each of the first and second electrodes ELT1 and ELT2, and may include an opening which exposes another area of each of the first and second electrodes ELT1 and ELT2.

In an embodiment, the first insulating layer INS1 may be primarily formed to cover the overall surfaces of the first and second electrodes ELT1 and ELT2. After the light emitting elements LD are supplied and aligned on the first insulating layer INS1, the first insulating layer INS1 may be partially open to expose the first and second electrodes ELT1 and ELT2 in the first and second contactors CNT1 and CNT2, as illustrated in FIG. 9 a . Alternatively, the first insulating layer INS1 may be patterned in the form of an individual pattern which is sectionally disposed under the light emitting elements LD after the supply and alignment of the light emitting elements LD have been completed.

In other words, the first insulating layer INS1 may be interposed between the first and second electrodes ELT1 and ELT2 and the light emitting elements LD, and may expose at least one area of each of the first and second electrodes ELT1 and ELT2. After the first and second electrodes ELT1 and ELT2 are formed, the first insulating layer INS1 may be formed to cover the first and second electrodes ELT1 and ELT2, so that it is possible to prevent the first and second electrodes ELT1 and ELT2 from being damaged or to prevent metal from being precipitated in a subsequent process. Furthermore, the first insulating layer INS1 may stably support each light emitting element LD. In an embodiment, the first insulating layer INS1 may be omitted.

The light emitting elements LD may be supplied to and aligned in the emission area EMA on which the first insulating layer INS1 is formed. For example, a plurality of light emitting elements LD may be supplied to the emission area EMA through an inkjet method or the like, and the light emitting elements LD may be aligned between the first and second electrodes ELT1 and ELT2 by predetermined alignment voltages (or alignment signals) applied to the first and second electrodes ELT1 and ELT2.

The bank BNK may be disposed on the first insulating layer INS1. For example, the bank BNK may be formed between other sub-pixels to enclose the emission area EMA of the sub-pixel SPX, so that a pixel defining layer for defining the emission area EMA of the sub-pixel SPX may be formed.

In an embodiment, the bank BNK may be formed to have a second height greater than a first height of the first and second partition walls PW1 and PW2. In this case, at the step of supplying the light emitting elements LD to each emission area EMA, the bank BNK may function as a dam structure configured to prevent a solution mixed with the light emitting elements LD from being drawn into the emission area EMA of an adjacent sub-pixel SPX or control the amount of solution such that a constant amount of solution is supplied to each emission area EMA.

The bank BNK may be formed to prevent light emitted from each emission area EMA from entering an adjacent emission area EMA and causing optical interference. To this end, the bank BNK may be formed to prevent light emitted from the light emitting elements LD of each sub-pixel SPX from passing through the bank BNK.

In some embodiments, the bank BNK may not be disposed between the sub-emission areas EMA_S1 and EMA_S2 (refer to FIG. 7 ), but the present disclosure is not limited thereto.

The second insulating layer INS2 may be disposed over the light emitting elements LD, particularly, the light emitting elements LD aligned between the first and second electrodes ELT1 and ELT2, and may expose the first and second ends EP1 and EP2 of the light emitting elements LD. For example, the second insulating layer INS2 may be partially disposed only over some areas of the light emitting elements LD without covering the first and second ends EP1 and EP2 of the light emitting elements LD. The second insulating layer INS2 may be formed in an independent pattern in each emission area EMA, but the present disclosure is not limited thereto. Furthermore, as illustrated in FIG. 9 a , if space is present between the first insulating layer INS1 and the light emitting elements LD before the second insulating layer INS2 is formed, the space may be filled with the second insulating layer INS2. Consequently, the light emitting elements LD may be more stably supported.

The first and second contact electrodes CNE1 and CNE2 may be disposed on the first and second electrodes ELT1 and ELT2 and the first and second ends EP1 and EP2 of the light emitting elements LD. In an embodiment, the first and second contact electrodes CNE1 and CNE2 may be disposed on the same layer, as illustrated in FIG. 9 a . In this case, although the first and second contact electrodes CNE1 and CNE2 are formed through the same process using the same conductive material, the present disclosure is not limited thereto.

The first and second contact electrodes CNE1 and CNE2 may respectively electrically connect the first and second ends EP1 and EP2 of the light emitting elements LD to the first and second electrodes ELT1 and ELT2.

For example, the first contact electrode CNE1 may be disposed on the first electrode ELT1 to make contact with the first electrode ELT1. For example, the first contact electrode CNE1 may be disposed to contact the first electrode ELT1 on one area of the first electrode ELT1 that is not covered by the first insulating layer INS1. Furthermore, the first contact electrode CNE1 may be disposed on the first end EP1 of at least one light emitting element adjacent to the first electrode ELT1, e.g., on the respective first ends EP1 of a plurality of light emitting elements LD so that the first contact electrode CNE1 can contact the first ends EP1. In other words, the first contact electrode CNE1 may be disposed to cover the first ends EP1 of the light emitting elements LD and at least one area of the corresponding first electrode ELT1. Hence, the first ends EP1 of the light emitting elements LD may be electrically connected to the first electrode ELT1.

Likewise, the second contact electrode CNE2 may be disposed on the second electrode ELT2 to contact the second electrode ELT2. For example, the second contact electrode CNE2 may be disposed to contact the second electrode ELT2 on one area of the second electrode ELT2 that is not covered by the first insulating layer INS1. Furthermore, the second contact electrode CNE2 may be disposed on the second end EP2 of at least one light emitting element adjacent to the second electrode ELT2, e.g., on the second ends EP2 of a plurality of light emitting elements LD so that the second contact electrode CNE2 can contact the second ends EP2. In other words, the second contact electrode CNE2 may be disposed to cover the second ends EP2 of the light emitting elements LD and at least one area of the corresponding second electrode ELT2. Hence, the second ends EP2 of the light emitting elements LD may be electrically connected to the second electrode ELT2.

The third insulating layer INS3 may be formed and/or disposed on one surface of the base layer SUB1 on which the first and second partition walls PW1 and PW2, the first and second electrodes ELT1 and ELT2, the light emitting elements LD, the first and second contact electrodes CNE1 and CNE2, and the bank BNK are formed, so that the third insulating layer INS3 may cover the first and second partition walls PW1 and PW2, the first and second electrodes ELT1 and ELT2, the light emitting elements LD, the first and second contact electrodes CNE1 and CNE2, and the bank BNK. The third insulating layer INS3 may include a thin-film encapsulation layer including at least one inorganic layer and/or organic layer, but the present disclosure is not limited thereto. In some embodiments, at least one overcoat layer, which is not illustrated, may be further disposed over the third insulating layer INS3.

In an embodiment, each of the first to third insulating layers INS1, INS2, and INS3 may have a single-layer or multi-layer structure, and include at least one inorganic insulating material and/or organic insulating material. For example, each of the first to third insulating layers INS1, INS2, and INS3 may include various kinds of well-known organic/inorganic insulating materials as well as SiNx, and the constituent material of each of the first to third insulating layers INS1, INS2, and INS3 is not particularly limited. The first to third insulating layers INS1, INS2, and INS3 may include different insulating materials, or at least some of the first to third insulating layers INS1, INS2, and INS3 may include the same insulating material.

In embodiments, the first and second contact electrodes CNE1 and CNE2 may be disposed on different layers.

Referring to FIG. 9 c , the first contact electrode CNE1 may be disposed in the sub-pixel area SPA in which the second insulating layer INS2 is disposed. In an embodiment, the first contact electrode CNE1 may be disposed on the first electrode ELT1 disposed in the corresponding sub-pixel area SPA such that the first contact electrode CNE1 contacts one area of the first electrode ELT1. Furthermore, the first contact electrode CNE1 may be disposed on the first end EP1 of at least one light emitting element LD disposed in the corresponding sub-pixel area SPA such that that the first contact electrode CNE1 contacts the first end EP1. Due to the first contact electrode CNE1, the first end EP1 of at least one light emitting element LD disposed in the sub-pixel area SPA may be electrically connected to the first electrode ELT1 disposed in the corresponding sub-pixel area SPA.

A fourth insulating layer INS4 may be disposed in the sub-pixel area SPA in which the first contact electrode CNE1 is disposed. In an embodiment, the fourth insulating layer INS4 may cover the second insulating layer INS2 and the first contact electrode CNE1 that are disposed in the corresponding sub-pixel area SPA.

In an embodiment, the fourth insulating layer INS4 may have a single-layer or multi-layer structure, and include at least one inorganic insulating material and/or organic insulating material, in a manner similar to that of the first to third insulating layers INS1, INS2, and INS3. For example, the fourth insulating layer INS4 may include various kinds of well-known organic/inorganic insulating materials including SiNx. Furthermore, the fourth insulating layer INS4 may include insulating material different from that of the first to third insulating layers INS1, INS2, and INS3, or may include the same insulating material as that of at least some of the first to third insulating layers INS1, INS2, and INS3.

The second contact electrode CNE2 may be disposed in each sub-pixel area SPA in which the fourth insulating layer INS4 is disposed. In an embodiment, the second contact electrode CNE2 may be disposed on the second electrode ELT2 disposed in the corresponding sub-pixel area SPA such that the second contact electrode CNE2 contacts one area of the second electrode ELT2. Furthermore, the second contact electrode CNE2 may be disposed on the second end EP2 of at least one light emitting element LD disposed in the corresponding sub-pixel area SPA such that that the second contact electrode CNE2 contacts the second end EP2. Due to the second contact electrode CNE2, the second end EP2 of at least one light emitting element LD disposed in each sub-pixel area SPA may be electrically connected to the second electrode ELT2 disposed in the corresponding sub-pixel area SPA.

In an embodiment, each of the first and second partition walls PW1 and PW2 may have various shapes. For example, as illustrated in FIG. 9 c , each of the first and second partition walls PW1 and PW2 may have a cross-sectional shape of a trapezoid that is reduced in width from a bottom to a top thereof. Alternatively, as illustrated in FIG. 9 d , each of the first and second partition walls PW1 and PW2 may have a semicircular or a semielliptical cross-section that is reduced in width from a bottom to a top thereof.

Next, a display device in accordance with another embodiment will be described. Hereinafter, description of the light source unit LSU will be made centered on the first sub-pixel SPX1. Furthermore, the duplicated description of the components shown in FIGS. 1 to 9 will be omitted herein, and the same or similar reference numerals are used.

FIG. 10 is a plan view illustrating another example of the sub-pixel included in the display device of FIG. 4 . A first sub-pixel SPX1 of FIG. 10 , except an emission area EMA, may be substantially the same as the first sub-pixel SPX1 of FIG. 7 . Therefore, repetitive explanation thereof will be omitted.

Referring to FIG. 10 , a first electrode ELT1 and a second electrode ELT2 in accordance with the present embodiment each may have a zigzag shape. The first electrode ELT1 and the second electrode ELT2 each may include linear portions STR1 and STR2 which extend in diagonal directions with respect to the first direction DR1 and the second direction DR2. The first electrode ELT1 and the second electrode ELT2 may include the linear portions STR1 and STR2 which extend in different directions. Extending in different directions, two adjacent linear portions STR1 and STR2 may meet to form a bent portion.

The light emitting elements LD each may be aligned in a normal direction with respect to a direction in which the first electrode ELT1 and the second electrode ELT2 extend, and the alignment direction thereof may be changed depending on the aligned position thereof. Consequently, the viewing angle of the display device may be improved.

FIG. 11 is a plan view illustrating another example of the sub-pixel included in the display device of FIG. 4 .

Referring to FIG. 11 , a first electrode ELT1 and a second electrode ELT2 in accordance with the present embodiment each may include linear portions STR1 and STR2 which extend in diagonal directions with respect to the first direction DR1 and the second direction DR2, and linear portions STR3 which extends in the second direction DR2. The first electrode ELT1 and the second electrode ELT2 each may include the linear portions STR3 each of which extends in the second direction DR2 between two linear portions STR1 and STR2 extending in the diagonal directions.

The alignment directions of the light emitting elements LD may be changed depending on the aligned positions thereof. Consequently, the viewing angle of the display device may be improved in the same manner as that of the previous embodiments.

FIG. 12 is a plan view illustrating another example of the sub-pixel included in the display device of FIG. 4 . FIG. 13 is a view for describing shapes of a first electrode and a second electrode of FIG. 12 .

Referring to FIGS. 12 and 13 , a first electrode ELT1 and a second electrode ELT2 in accordance with the present embodiment each may have a curved shape including an inflection point INFL. In the first electrode ELT1 and the second electrode ELT2, curved portions between adjacent inflection points INFL each may have a circular arc shape. For example, each of the first electrode ELT1 and the second electrode ELT2 may have a shape formed by dividing an electrode having a circular ring shape into two or four equal parts and recombining the divided parts. A part HARC (ARC3 and ARC4) of each of the first electrode ELT1 and the second electrode ELT2 may have a semicircular arc shape, and remaining parts ARC1 and ARC2 thereof each may have a quadrant arc shape. Each of the first electrode ELT1 and the second electrode ELT2 may have a shape in which opposite ends thereof are respectively formed of the parts ARC1 and ARC2 each having a quadrant arc shape and the part HARC (ARC3 and ARC4) having a semicircular arc shape is connected between the parts ARC1 and ARC2 each having a quadrant arc shape.

The alignment directions of the light emitting elements LD may be changed depending on the aligned positions thereof. Consequently, the viewing angle of the display device may be improved in the same manner as that of the previous embodiments.

FIG. 14 is a plan view illustrating another example of the sub-pixel included in the display device of FIG. 4 .

Referring to FIG. 14 , each of a first electrode ELT1 and a second electrode ELT2 in accordance with the present embodiment is different from that of the embodiment of FIG. 12 in that each of the opposite ends thereof is formed of a quadrant arc-shaped part and a plurality of semicircular arc-shaped parts are connected between the opposite ends.

The first electrode ELT1 and the second electrode ELT2 in accordance with the present embodiment may respectively have shapes formed by repeatedly connecting the first electrodes ELT1 and the second electrodes ELT2 of FIG. 12 in the second directions DR2.

The alignment directions of the light emitting elements LD may be changed depending on the aligned positions thereof. Consequently, the viewing angle of the display device may be improved in the same manner as that of the previous embodiments. In the present embodiment, the size of the emission area of the sub-pixel may be adjusted.

FIGS. 15 to 17 are plan views illustrating other examples of a sub-pixel included in the display device of FIG. 4 . In the drawings, illustration of light emitting elements is omitted.

Referring to FIGS. 15 and 17 , in accordance with an embodiment, a first electrode ELT1 and a second electrode ELT2 each may have a portion having a different width. For example, opposite ends of each of the first electrode ELT1 and the second electrode ELT2 and/or a portion thereof in which an inflection point is formed may be greater in width than adjacent portions thereof.

The alignment directions of the light emitting elements may be changed depending on the aligned positions thereof. Consequently, the viewing angle of the display device may be improved in the same manner as that of the previous embodiments. As illustrated in the embodiment of FIG. 17 , the size of the emission area of the sub-pixel may be adjusted by repeatedly connecting the first electrodes ELT1 and the second electrodes ELT2.

FIGS. 18 and 19 are plan views illustrating other examples of the sub-pixel included in the display device of FIG. 4 . In the drawings, illustration of light emitting elements is omitted.

A first electrode ELT1 and a second electrode ELT2 in accordance with the present embodiment each may have various shapes by connecting quadrant arc-shaped parts by applying the embodiment of FIGS. 12 and 13 . The shape illustrated in FIGS. 18 and 19 is only for illustrative purposes and is not limited to the illustrated shape.

FIGS. 20 a to 20 d are circuit diagrams illustrating another example of the unit pixel included in the sub-pixel of FIG. 5 .

Referring to FIGS. 20 a to 20 d , disposition of the light source unit LSU differs from that of the circuit diagram of FIGS. 6 a to 6 d . Light emitting elements LD in each light source unit LSU may be connected in a serial and parallel combination structure.

Each light source unit LSU may include light emitting elements LD connected in series to each other. Since the light emitting elements LD are connected in series to each other, voltage distribution efficiency may be improved, and capacity design of the first transistor (or driving transistor) T1 may be facilitated. Furthermore, since the light emitting elements LD may be connected in a serial and parallel combination shape, power loss attributable to line resistance may be mitigated. Although in the drawing there is illustrated an example in which three light emitting elements LD are connected in series, the number of light emitting elements LD is not limited thereto.

Hereinafter, the shapes of electrodes in the emission area to which the circuit diagrams of FIGS. 20 a to 20 d can be applied will be described. In the following embodiments, there will be described examples in which each of the sub-pixels includes one unit pixel.

FIGS. 21 to 30 are plan views illustrating various examples of the sub-pixel (or the unit pixel) to which the examples of FIGS. 20 a to 20 d may be applied. The shape of a first electrode and a second electrode of FIGS. 21 to 30 may have the same shape as that of FIGS. 7, 10 to 12 , and 14 to 19, so that repetitive explanation thereof will be omitted.

In the present embodiments, the first electrode ELT1 and the second electrode ELT2 may be respectively defined as electrodes which extend from or are directly connected to the first connection electrode CNL1 and the second connection electrode CNL2.

The first electrode ELT1 and the second electrode ELT2 may be spaced apart from each other by a predetermined distance and disposed in parallel to each other. At least one island electrode ILT1, ILT2 may be disposed between the first electrode ELT1 and the second electrode ELT2. In the present embodiment, there will be described an example in which two island electrodes ILT1 and ILT2, i.e., a first island electrode ILT1 and a second island electrode ILT2, are disposed between the first electrode ELT1 and the second electrode ELT2. The embodiment is not limited to the number or shape of the island electrodes ILT1 and ILT2.

The first island electrode ILT1 and the second island electrode ILT2 may be disposed between the first electrode ELT1 and the second electrode ELT2 such that the first electrode ELT1, the second electrode ELT2, the first island electrode ILT1, and the second island electrode ILT2 are spaced apart from each other by predetermined distances and are parallel to each other.

In an embodiment, the distances between the first electrode ELT1, the second electrode ELT2, the first island electrode ILT1, and the second island electrode ILT2 may be the same as each other.

In an embodiment, the first island electrode ILT1 and the second island electrode ILT2 may be disposed on the same layer as that of the first electrode ELT1 and the second electrode ELT2. The first island electrode ILT1 and the second island electrode ILT2 may be patterned along with the first electrode ELT1 and the second electrode ELT2.

The first island electrode ILT1 and the second island electrode ILT2 are not directly connected with the first connection electrode CNL1 and the second connection electrode CNL2, and may be electrically connected to the first connection electrode CNL1 and the second connection electrode CNL2 by light emitting elements LD disposed between the first electrode ELT1 and the second electrode ELT2.

The alignment directions of the light emitting elements LD may be changed depending on the aligned positions thereof. Consequently, the viewing angle of the display device may be improved in the same manner as that of the previous embodiments. Furthermore, the display device may have the above-stated effects that are obtained by connecting the light emitting elements LD in a serial and parallel combination structure.

FIG. 31 is a circuit diagram illustrating another example of the unit pixel included in the sub-pixel of FIG. 5 . FIG. 32 is a plan view illustrating an example of the sub-pixel of FIG. 31 . In the present embodiment, there will be described examples in which each of the sub-pixels includes three unit pixels.

Referring to FIG. 31 , the sub-pixel SPX may include light emitting elements LD1 to LDk configured to emit light at a luminance corresponding to a data signal. Furthermore, the sub-pixel SPX may include a common circuit PXC_C and sub-pixel circuits PXC_S1 to PXC_Sk configured to independently drive the respective light emitting elements LD1 to LDk.

The common circuit PXC_C of the sub-pixel SPX may provide, to the sub-pixel circuits PXC_S1 to PXC_Sk, a data signal provided from the data line Dj in response to a scan signal provided from the scan line Si.

The common circuit PXC_C may include a second transistor T2.

Each of the sub-pixel circuits PXC_S1 to PXC_Sk may store a data signal provided from the common circuit PXC_C, and provide driving current corresponding to the stored data signal to the corresponding light emitting element (i.e., one of the light emitting elements LD1 to LDk).

In an embodiment, the sub-pixel circuits PXC_S1 to PXC_Sk may include the first transistor T1, the third transistor T3, and the storage capacitor Cst that are described with reference to FIG. 6 d.

For example, the first sub-pixel circuit PXC_S1 may provide, to a first light emitting element string LDS1 (or a first sub-light source unit), first driving current corresponding to a data signal provided from the common circuit PXC_C. Likewise, the second sub-pixel circuit PXC_S2 may provide, to a second light emitting element string LDS2, second driving current corresponding to a data signal provided from the common circuit PXC_C. The k-th sub-pixel circuit PXC_Sk may provide, to a k-th light emitting element string LDSk, k-th driving current corresponding to a data signal provided from the common circuit PXC_C. There is illustrated an example in which each light emitting element string includes three light emitting elements connected in series to each other.

Each of the sub-pixel circuits PXC_S1 to PXC_Sk may store a data signal in the storage capacitor Cst, and provide driving current corresponding to the corresponding data signal to the corresponding light emitting element (i.e., the corresponding light emitting element of the light emitting elements LD1 to LDk). Therefore, the light emitting elements LD1 to LDk may more uniformly emit light.

Referring to FIG. 32 , the emission area EMA may be divided into first to third sub-emission areas EMA.

In embodiments, the first electrode ELT1 may be disposed in each of the sub-emission areas EMA_S1, EMA_S2, and EMA_S3. The second electrode ELT2 may be disposed in the entirety of the emission area EMA, i.e., across the sub-emission areas. The first island electrode ILT1 and the second island electrode ILT2 may be disposed between the first and second electrodes ELT1 and ELT2 in the corresponding sub-emission area (e.g., in the first sub-emission area EMA_S1).

The first electrode ELT1, the second electrode ELT2, and the island electrodes ILT1 and ILT2 each may have a single-layer or multi-layer structure. Furthermore, each of the first electrode ELT1, the second electrode ELT2, and the island electrodes ILT1 and ILT2 may protrude in an upward direction (or a height-wise direction or a thickness-wise direction of the base layer SUB1) by a partition wall that is disposed to overlap with the corresponding electrode.

The light emitting elements LD each may be disposed between two adjacent electrodes of the first electrode ELT1, the second electrode ELT2, and the island electrodes ILT1 and ILT2 and electrically connected to each of the two adjacent electrodes. For example, a light emitting element LD may be disposed between the first electrode ELT1 and the first island electrode ILT1 adjacent to the first electrode ELT1. A first end of the light emitting element LD may be electrically connected to the first electrode ELT1, and a second end of the light emitting element LD may be electrically connected to the first island electrode ILT1. Likewise, a light emitting element LD may be disposed between the first island electrode ILT1 and the second island electrode ILT2 adjacent to the first island electrode ILT1. A first end of the light emitting element LD may be electrically connected to the first island electrode ILT1, and a second end of the light emitting element LD may be electrically connected to the second island electrode ILT2. Likewise, a light emitting element LD may be disposed between the second island electrode ILT2 and the second electrode adjacent to the second island electrode ILT2. A first end of the light emitting element LD may be electrically connected to the second island electrode ILT2, and a second end of the light emitting element LD may be electrically connected to the second electrode. In this way, the light emitting elements LD in the first sub-emission area EMA_S1 may be connected in series between the first and second electrodes ELT1 and ELT2.

The first electrode ELT1, the second electrode ELT2, and the island electrodes ILT1 and ILT2 each may extend, with a bent portion. Each of the first electrode ELT1, the second electrode ELT2, and the island electrodes ILT1 and ILT2 may be provided in various shapes, in the same manner as that of the above-described embodiments.

Although FIG. 32 illustrates that the light emitting elements LD are connected in series in one sub-emission area (e.g., the first sub-emission area EMA_S1), the light emitting elements LD are not limited thereto. For example, in the one sub-emission area, at least some of the light emitting elements LD may be connected in parallel to other light emitting elements. In other words, in FIG. 32 , the light emitting elements LD in the one sub-emission area may be arranged in a serial/parallel combined connection structure.

Although the embodiments of the present disclose have been disclosed, those skilled in the art will appreciate that the present disclose can be implemented as other concrete forms, without departing from the scope and spirit of the disclose as disclosed in the accompanying claims. Therefore, it should be understood that the exemplary embodiments are only for illustrative purpose and do not limit the bounds of the present disclosure. 

1. A display device comprising: a first connection electrode extending in a first direction, and electrically connected to a first power line to which a first power supply is applied; a second connection electrode spaced apart from the first connection electrode, and electrically connected to a second power line to which a second power supply is applied; a first electrode extending from the first connection electrode; a second electrode extending from the second connection electrode, and disposed in parallel to the first electrode with a predetermined distance therebetween; and a plurality of light emitting elements each including a first end electrically connected to the first electrode, and a second end electrically connected to the second electrode, wherein each of the first electrode and the second electrode includes a bent portion.
 2. The display device according to claim 1, wherein the first electrode and the second electrode respectively extend from the first connection electrode and the second connection electrode in a second direction intersecting the first direction.
 3. The display device according to claim 2, wherein the bent portion has a shape protruding in the first direction.
 4. The display device according to claim 3, wherein each of the first electrode and the second electrode has a curved shape or a zigzag shape.
 5. The display device according to claim 4, wherein each of the first electrode and the second electrode has a shape formed by connecting a plurality of quadrant arcs.
 6. The display device according to claim 4, wherein each of the first electrode and the second electrode includes a connection portion having a shape formed by connecting a plurality of quadrant arcs, and wherein an inflection point is included in the connection portion.
 7. The display device according to claim 1, wherein each of the light emitting elements comprises a rod-shaped light emitting diode having a size ranging from a nanoscale to a microscale.
 8. The display device according to claim 7, wherein at least some of the plurality of light emitting elements are aligned such that a longitudinal direction thereof corresponds to a normal direction with respect to a direction in which the first electrode and the second electrode extend.
 9. The display device according to claim 1, wherein the first electrode or the second electrode includes a portion having a different width.
 10. The display device according to claim 1, comprising at least one island electrode disposed between the first electrode and the second electrode without being directly connected to the first connection electrode or the second connection electrode.
 11. The display device according to claim 10, wherein some of the plurality of light emitting elements are disposed between the first electrode and the at least one island electrode, and wherein other some of the plurality of light emitting elements are disposed between the second electrode and the at least one island electrode.
 12. The display device according to claim 11, wherein the at least one island electrode is disposed in parallel to the first electrode and the second electrode with a predetermined distance therebetween.
 13. The display device according to claim 12, wherein the at least one island electrode includes a bent portion.
 14. The display device according to claim 10, wherein the plurality of light emitting elements are connected in series and parallel to each other.
 15. The display device according to claim 1, wherein each of the first electrode and the second electrode further includes a linear portion extending in a second direction intersecting the first direction.
 16. A display device comprising: a substrate including an emission area; a first electrode disposed in the emission area of the substrate; a second electrode disposed in the emission area of the substrate on a layer identical with the first electrode, and configured to face the first electrode, and spaced apart from and electrically separated from the first electrode; and a plurality of light emitting elements disposed between the first electrode and the second electrode in a plan view, wherein each of the first electrode and the second electrode includes a bent portion in a plan view.
 17. The display device according to claim 16, further comprising: a first contact electrode configured to connect a first end of each of the light emitting elements to the first electrode; and a second contact electrode configured to connect a second end of each of the light emitting elements to the second electrode.
 18. The display device according to claim 16, further comprising a first island electrode and a second island electrode disposed between the first electrode and the second electrode, wherein distances between the first electrode, the first island electrode, the second island electrode and the second electrode are equal to each other.
 19. The display device according to claim 18, wherein the first electrode, the first island electrode, the second island electrode and the second electrode are disposed in parallel to each other.
 20. The display device according to claim 19, wherein each of the first island electrode and the second island electrode includes a bent portion. 